The present invention relates generally to pneumatic tires, and more particularly to tires having a "run-flat" capability.
Generally speaking, tires of the "run-flat" variety employ various inner assemblies for supporting the sidewalls at least partially after tread-puncture, and for retaining the bead regions wedged against the annular flanges of the vehicular wheels upon which such tires are mounted. Thus, tires of the "run-flat" variety can be used somewhat effectively over various distances at certain maximum permissible speeds.
A disadvantage associated with conventional "run-flat" tires is that they are utilized at air-pressures, after tread-puncture, which are substantially less than their normal-rated puncture-free inflation pressure, and often at no air-pressure at all. As a result, when such tires are punctured and run flat in a wider, deformed condition, the loads thereon are not properly balanced and pneumatically supported. The components of such tires, such as the sidewalls and tread, are therefore often subjected to extreme stress and wear, and in the wider, deformed condition thereof are likely to be punctured once again, and are likely to fail earlier than desirable after the tire is repaired and run once again in a fully inflated condition.